Yeah, I wouldn’t go putting the loan bike on the Bay. As is usually the case, both customer and retailer are obliged to exercise the 3 R’s.
A former forum member would have probably banged on about demanding your refund immediately. And if that happens, then great. However, in the case where no refund is given and the matter goes to arbitration. The person reviewing the case will want to see both sides having tried to settle the matter, before going straight to court. Which is why most times, one goes through Repair, Replace and finally, Refund.
Also, I would not accept the shop deferring the issue to the Manufacturer / supplier. The shop sold the bike to you at a price which included their profit. Therefore, they are responsible as this is the risk any retailer takes when selling goods. If its a good product, then no one claims for repairs / refunds, etc, and a profit is made by the shop.
If its a poor product, then the shop sorts it and they decide whether to continue selling a troublesome product.
So, before getting to the stage where legal redress may be your only option. Try to come to an amicable agreement with the shop. Do not accept the shop trying to pass responsibility to the supplier / manufacturer. The shop must sort it for you.
Sorry to here that your longer rides may be scuppered for a while.
Good luck.